(a) Field of the Invention
The present invention relates to a method for inspecting a cell (or a battery).
(b) Description of the Related Art
A cell (but hereinafter called, a battery) in which an electrode laminate constituted by a plurality of electrodes and separators grasped between the mutual electrodes is sealed by means of a pair of laminate films is present.
In such a battery as described above, if a short circuit between a positive electrode and a negative electrode occurs, there is a possibility of not achieving a sufficient function as the battery. In order to avoid this possibility, Patent Documents 1 and 2 describe that a voltage between the positive electrode and the negative electrode is applied in a state before the electrode laminate is inserted into an inside of a package constituted by laminated films and an electrode solution is poured in the package to measure an electric current to detect a presence or absence of the short circuit.
According to Patent Documents 1 and 2, a defective product can be removed by detecting the short circuit between the positive electrode and the negative electrode. However, generally, the laminate films have inner layers of metallic layers such as aluminum layers. Even in a case where the short circuit occurs between the metallic layers within the laminate films and the positive electrode or the negative electrode, there is a possibility of not performing the sufficient function as the battery.
Patent Documents 3 and 4 describe that a presence or absence of the short circuit is detected by measuring an insulation resistance between the metallic layer within a laminate film and the positive electrode or the negative electrode in a state in which an electrode laminate and an electrolyte solution are inserted into an inside of a package constituted by the laminate film and the package is sealed so that the battery is completed.